Interchangeable matrix tread vulcanizing mold



May 15, 1945.

INTERCHANGEABLE MATRIX TREAD VULCANIZING MOI .|D

Filed March 22, 1943 5 Sheets-Sheet l ATTORNEYS 3 Sheets-Sheet 2 I III-\IIVENTQR Z. H. Glynn MM ATTORNEYS May 15,4945. E. A. GLYNN V INTERCHANGEABLE MATRIX TREAD \IULCANIZING MOLD Filed marchzz', 194:5

lllllllllll Illl lllllliii Q Patented May 15, 1945 mmaonnne'snnm MATRIX TREAD it mionmzme MOLD .Edwin A. Glynn, 'Lodi, Calif., .assignor to. Super Mold Corporation .of California, Lodi, Calif :.a

corporation "of California l Application March 22, 1943,lSerial No. 479,999'

*s olzims. (or. 18-18) a This inventionrelates-in general to the am :of

Jtire retreading rand recapping, identified herein--- after generally as tread vnlcanizing, and impar- -ticular the present invention is directed .to an improved tread vulcanizing mold.

Under certain conditions, as for example in the aircraft industry where tire sizes are many,

it :is desirable to have available :a :tread vulcanizing mold which i widely variable in its time size capacity. It is therefore one of the objects of this :invention to provide a tread yulcanizing :mold which is arranged tor the ready-reception .of \tread-vulcanizing matrix assemblies of different sizes, both diametrally and transversely.

i A (further object of this invention is the proyisionof a tread vulcanizingmold which includes, in combination with a bed plate and head plate arrangement wherein one of said plates is movable axially and power actuated, \an initially separate matrix assembly forcefully engaged be- ,tweensaidplates in centered relation; said matrix assembly comprising )full circle matching halves and the assembly being held in placeradially and axially of said plates by unique securing means. Such securing means comprises .circumferentiallyspaced locking clamps or dogs engaged between corresponding halves of the .matrixassembly and said plates, said clamps beingadjustr tblelax'ially of the mold, whereby toaccommoldate matrixassemblies of difierentldiameterabut are normally iheld in lplace by a securing belt which extends throngharadial slot in the corresponding one oftheplates. v

An additionallobject of thisinvention is to provide a tread vulcanizing mold which includes a bed plate, a concentric relatively "axially movable head plate, a matrix assembly .adaptedlto 'be iorcefully engaged between said plates, antiseparate means, independent of said plates, operative .to heat said matrix assembly; the plates andengaged portions or the matrix assembly lbeing formed in unique structural arrangement so as to minimizehea't exchange or transfer from s the matrix assembly .to the ,p'lates wherebyto increase the effectiveness and economy of the mold. I

A still iurtherobjiect of this invention is to provide a tread wilcanizing moldtas .infltheprecedingparagraphin which the adjacent Iacesof the plates are .iormed with .a plurality of .circumier entially spaced, radially extending ribs which project toward and intersect the mold assembly; the engaged surface of the latter being .iannul'arly channeledsoas .to reduce theareaof contact with said ribs. v i

It is also an object of this invention to provide a .unique selectively controlled drive mechanism for the herein described tread yulcanizing mold,

said mechanism'belng operative to cause relative separating or approaching movement of the 'matrix assembly engaging plates, and in the latter event to cause forcefulengagement of said assembly' in clamped. relation between said plates.

This invention has, for an additional object, the provision of a tread yulcan'izing mold which includes a bed plate, a concentric head plate mounted for relative axial movement, power actualted me'ans to effect-such movement, and an initially separate matrix assembly adapted to be forcefully clamped between said plates; said asse'mblyhav-ing heatingrneans associated therewithindependently-of the plates.

These ob jec'ts I accomplish by means of such structure-andrelative arrangementof parts as will fully appear by a -perusal "of the following specification andclaims.

In the drawings similar characters of reference indicate correspondingparts in thesevera'lyiews:

Figure Cl is 'a plan view of the improved mold;

the head'plate being mainly'bro'ken away. l Figure? is a sectional elevation on *line 2-2 of Fig. '1. x i

"FigureB is an enlarged fragmentarycross sec- Figure l is a fragmentary sectional elevation,

' enlarged, of the clutch un'it employed between the drivemo'tor and the head plate actuating meohanism. i

proved tread yulcanizing mold comprises-a circular bed plate, indicated generally at l, said bed plate being {disposed horizontally and including, "in integral relation, a :cen tra-l hub 2 and a depending peripheral flange 3. Ciroum'ferentially spaced strengthening webs 4 extend radially between thelhubfi and the flange 3. The bed plate is supported some distanceabove the floor by *legsi. i

matchinghead plate "-6 is disposed in 'adi acent but spaced relation above the "bed plate and in axial a'linement with the latter; adjacent faces, indicated generally at F, o: the plates "I and 6 being parallel. The head plate -6 likewise includes a hub 1, an upstanding peripheral flange i3 and strengthening webs 9 extending there'betweenythe "hub, flange and "webs of the plates Tl andi projecting in opposite directions from the faces -F.

i'Ihe head plate 6, is supported above the bed plate for-axial movement by a pair ofvertical spindles 1.0 which :are frctata-bly but axially ime movably journal'ed in connection with the bed plate bykbearing means indicated generally at 1 I. These spindles I'll project vertically some 'distance above the bed I and threadingly engage,

as at "l-Z, in vertical sleeves "I 3 'fixed'in the head either raised or lowered relative to the bed plate the bed plate.

and for the purpose as will hereinafter appear.

, Simultaneous rotationof thespindles NJ is accomplished through the medium of a drive mechanism which comprises the following:

A bevel gear- I4 is secured on the lower end-of 1 speed, from a motor 19 mounted on and de-" pending from the bed plate; a clutch unit, indicated generally at 20, being interposed between the gear l8 and the motor l9. The motor 19 is of reversible type and is controlled by means of a manually actuated reversing switch 2| mounted at a suitable exposed point on the mold and interposed in the current supply cable 22.

.The clutch unit 23 is shown in detail in Fig. 4, and comprises the following: I

The drive shaft 23 of motor l9 extendsaxially into and is keyed to the-elongated hub 24 of a radial clutch disc 25 formed integral with said hub. The other disc or element of the clutch is formed as'a shallow cup 26 having a clutch lining 21 of friction materialtherein; the clutch disc 25 seating in said cup 26.. The cup 26 has a pinion 28 rigidly mounted in axial connection therewith, said pinion 28 meshing in driving relation with the gear l8.

As will be apparent, limited axial movement of the cup 26 inlthe direction of the disc 25 will result in coupling of the clutch and rotation of the pinion 28 from the motor shaft 23. Con- Versely, movement of the cup in an opposite direction will uncouple the clutch. Such limited movement of the cup 26 is accomplished through the medium of a control shaft 29 which extends below the bed plate from a point beyond the pe- 1 riphery of the latter; said shaft being rotatably supported adjacent its outer end bya bracket 30; a radial hand lever 3| being fixed on shaft 29 beyond the bracket 30 and the periphery of Intermediate the pinion 28 and bracket 33 the shaft 29 terminates adjacent a fixed collar 32 which is tapped from endto end. A threaded bushing 331s pinned to shaft 29, as at 34, and is threaded through the fixed collar I purpose of simplicity.

late permits the mold to accommodate matrix assemblies of different dimensions axially.

While each mold will preferably include a number of matrix assemblies of different sizes, only one is here shown and described, for the Such matrix assembly comprises a pair of full-circle matching matrix .32. Shafts 29 and 23 are held in alinementand the pinion and clutch cup unit are supported by afloating shaft 290. seated at its ends in hub 24 and bushing 33 and extending axially throughthe pinion 28 and cup 26. By this construction,

driving of shaft 23 does nottend to rotate shaft 29. A thrust bearing unit 35 freely surrounds shaft 29a and is engaged between adjacent ends of pinion 28 and collar 32. i As will be obvious, swinging movement of the lever'3l causes the threaded bushing 33 to be shifted in a direction either toward or away from the pinion 28, and this movement is imparted to the pinion 28 and cup 26, resulting either in engagement or disengagement of the clutch. When the motor'is running in one'direction or the other, engagement of the clutch causes raising or lowering, respectively, of the head plate.

A tread vulcanizin matrix assembly, indicated generally at 36, is normally but removably disposed between the bed plate and head plate and plate, as shown in Fig. 3.

halves, indicated at 31, said halves normally being engaged in matching cooperating relation.

An annular locking bead and groove arrangement 38 normally prevents radial displacement of one matrix half relative to the other without restricting axial separation thereof. The matrix halves each includes a matrix skirt 39. The

inner surface of the matrix halves 31 and corre spending matrix skirts 39 form a continuous 4 tread vulcanizing surface 40.

Under some conditions the matrix skirts 39 are extended radially inwardly by tire sidewall retaining rings or skirt extensions 4! of full-circle configuration which engage at their outer periphery with the end of the corresponding skirt 39; said rings 4| being of such axial extent that when the outside thereof is fiush with the corresponding side of the adjacent matrix half, the inside of said rings is flush with and forms a continuation of the adjacent portionof sur face 40. v i

countersunk locating and retaining tongues 42 project radially outwardly from the outside of rings 4| in circumferentially spaced relation and seat in corresponding grooves in the adjacent portion of the corresponding matrix half. Consequently'the rings 4|, when mounted in connection with the matrix halves, are held against displacement axially inwardly.

When'in use the matrix assembly is centered and clamped between the bed plate and head Relative radial'displacement of the matrix assembly when the mold 15 in operation, or escape of either of the corresponding matrix halves from the corresponding plate when said halves are separated, is prevented by means of normally locked but radially adjustable clamps 43. A plurality of these clamps in ci-rcumferentially spaced relation is employed in connection with each matrix half. Each clamp is of generally L-shaped configuration with one leg of the clamp seating in an annular shoulderforming channel 44 in the periphery of the corresponding matrix half, and the other end of the clamp seats against the adjacent plate, the latter end of each clamp including a depending guide element 45 which engages in a radial groove 46 in the plate. A securing bolt 41 extends through the clamp intermediate its ends; the headed end of the bolt being lowermost and engaging from below against abutment flanges 48 which pro ject inwardly from opposite sides of the groove 46.

By virtue of the adjustable clamp arrangement above described, matrix assemblies of different diameters can be effectively clamped in connection with the plates.

The matrix halves each include a steam chamber '49 thereabout, each steam chamber having a separate inlet pipe 50, and an outlet pipe 51 connected therewith. Flexible supply and discharge conduits (not shown) are adapted for con nection with pipes 50 and 5|.

As the above heating means for the matrix assembly is independent of the bed plate I and semblies of different diameters therebetween, and

head plate 6, not only can the matrix assembly be removed and replaced with facility, but also t e. i l s i a n em can be m ye 9 minimize heat transfer or exchange between the matrix assembly and said plates.

The adjacent faces F of the bed plate land head plate fi are formed with a plurality of circumferentially spaced pairs of radially extending axially inwardly projecting ribs 52, while the en gaged surfaces of the matrix halves '31 and rings M are annularly channeled, as at 53. Thus the area of contact between the plates and the adjacent portions of the matrix assembly is not great. This is an important feature, as it minimizes heat exchange and substantially increases the effectiveness and economy of the mold.

In use, the matrix assembly is secured to the bed and head plates by the clamps 43, and the matrix halves axially separated. The tire T, to

. whichthe'new tread material M has previously been applied,is then seated in the lower matrix half, while the upper matrix half remains in vertically spaced relation. Thereafter the head plate Bis lowered to bring the upper matrix half into matching and cooperating relation with the asset forth herein.

lowerhalf, and to forcefully. clamp the matrix assembly between the plates [and 6. When the head plate 6 is brought into forceful engagement with the matrixassembly, the clutch unit Zllwill slip sufiiciently to prevent .damage to the motor I!) should the operator not immediately disengage said clutch unit by propermanipulation of le- A conventional air bag 54 is disposed inthe tire and retained in placeby a vulcanizing rim 55, here shown as'beingof the type known as an inside curing rim. Thebag 54 includes a valve stem 56 to which an air hose 5! is attached by i a quick coupling 58. The air hoseleads from a hand actuated control valve 59 mounted on the outside of the mold, said hose extending from said valve downwardly beneath the mold and thence upwardly through the hub 2 of the bed plate I,

Air pressure is supplied to the valve 59 by a conduit 60.. s v 1 Upon inflation of the air bag 54, the newly applied tread material M is forcefully pressed against thematrix surface 40, said surfacebeing heated from the steam chambers 49 to effect the.

vulcanizing process. As clearly shown in Fig, 3,

through, clamps securing each matrix half to the substantially fulfills the objects of the invention While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention as defined by the appended claims. i

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

S1. .A tread vulcanizing mold comprising a bed plate and a head plate disposed in adjacent facing relation and mounted for relative axial movernent, adjacent faces of said pIatesbeing parallel, an annular matrix assembly disposed between said plates and adapted to be forcefully engaged therebetween, and means, independent of the plates, operative to heat the matrix assembly;

the adjacent faces of the plates having radially extending axially and inwardly projecting ribs formed thereon in circumferentially spaced. re-

lation, and the engagedsides of the matrix as- I sembly being angularly channeled whereby said ribs intersect the channels so as to minimize heat transfer from the matrix.

2. A tread vulcanizing mold comprising a bed plate and a head plate disposed in adjacentfac ing relation andmounted for relative axial movement, adjacent faces of said plates being parallel, an annular matrix assembly disposed between said plates and adapted to beforcefully engaged therebetween said assembly. comprising full-circle matrix halves normally disposed in engaged matching relation, the plates having a. plurality of circumferentially spaced radial slotstherecorresponding plate and including bolts passing the surface 4i! conforms symmetrically to the tread of the tire. whereas the rings 4! engage the side walls S of the tire to prevent undesirable lateral expansion or stretching thereof.

When the vulcanizingprocesshas been completed the matrix assembly; is separated by raising thehead plate 6. whereupon the tire may be withdrawn from said. assembly.

Undercertain conditions it may bedesirable to employ manual means to actuate the head plate raising and lowering mechanism. To accomplish this, a hand wheel 61 is rotatably mounted on an extendedend portion of shaft H,

but is normally out of driving relation therewith. The wheel may, however, be broughtinto driving through said slots whereby the clamps arcadjustable radiallypf the mold, radially extending axiallyandinwardly projecting ribs formed on I asaid faces, said ribs being relativelynarrow and disposed along opposite sides of saidslots, the rib engaging sides of said matrix halves being annularly channeled to an extent that the unchane neled portions of said sides are relatively narrow radially-of said plates wherebytominimize the area of contact between the plates and the matrix assembly, and. means, independent of said plates,

operative to heat the matrix assembly.

3. A tread vulcanizingmoldcomprising a bed 1 plate and a head plate disposed in axially spaced plate is locked in facing relation, said plates, being mounted for. f power actuated relative axial movement, power means operative to effect such movement, an

initially separate matrix assembly seated on one plate and adapted to be forcefully engaged be tween said plates, means toheat said matrix. assembly, and means releasably securing the matrix assembly. in connection with at least one of l saidplates; said last .named means comprising a plurality of circumferentially spaced L-shaped clamps, a. shoulder on the matrix assembly adjacenteach clampand facing away from said I one plate,one leg of each clamp engaging said adjacent shoulder on the matrix assembly and" the other leg of each clamp seating on said one plate; there beingxa bolt connecting each clamp intermediate its ends with said one plate, each l of said bolts extending through a radial slot in said'one plate whereby upon loosening of; each bolt the correspondingclamp, together with said bolt, is adjustable radially of the moldbut re,

mains in connection therewith.

EDWINIA. GLYNN. 

